Paper roller mechanism



June 9, 1931. c w. CRUMRIN-E 1,809,024

PAPER ROLLER MECHANISM Filed Dec. 9, 1926 Patented June 9, 19 31 UNITED STATES PATENT OFFICE CHESTER, W. CRUMRINE, OF ROCHESTER, NEW YORK, ASSIGNOR TO ELECTROMATIO 'IYPEWRITERS, INCL, OF ROCHESTER, NEW YORK, A CORPORATION OF NEW YORK PAPER ROLLER MECHANISM Application filed December 9, 1926. Serial No. 153,588.

This invention relates to the rollers used to press the paper against the platen in a typewriter or similar machine.

The object of the invention is to provide a mechanism by which each of two parallel paper-rollers may be pressed against the paper with a force which is equal as to the two ends of the roller, regardless of variations in the thickness of the paper, while at the 0 same time the axes of the rollers are held substantially parallel with each other, and as nearly as possible parallel with the axis of the platen. To this end the invention consists in a construction, hereinafter more particularly described, by which the rollers are supported with freedom in every respect necessary for theirrelative compensatory movements, and in which the resilient pressure is applied tothe rollers through mechanism by which it is automatically equalized as between the two rollers and the two ends of each roller.

In the accompany ng drawings Fig. 1 is a plan-view of the mechanism embodying the present invention, with certain details shown in section. Fig. '2 is an end-view of the mechanism, together with the platen of a typewriter; and Fig. 3 is a detail view showingfthe loose pivotal connection between the so, front paper-roller and one of the end-levers. The invention is illustrated as embodied in a mechanism comprising two parallel paperrollers, which are pressed upwardly against the lower part of the platen in a well known manner. The rear roller 5 has a continuous surface, of rubber or other suitable material, while the front roller comprises a rod 6, upon which are three detached contact portions 7 These rollers cooperate with the of rubber. platen 8 of the typewriter, as shown in Fig. *2.

The two rollers are supported, at their ends, by two end-levers 9. Each end of the rear roller 5 has a pivotal connection with the rear end of the respective end-lever, by means of a trunnion 10 which is fitted so loosely in the lever that it may not only rotate, but also have the slight angular move-- ments necessary for compensation. Each lever 9 is perforated at an intermediate pointof its length, and a rod 11 is pivoted at its ends in these perforations, being loosely fitted as in the case of the trunni'ons lO, so as to permit slight angular as well as relative rotative movements of the end-levers.

In the arrangement so far described, it as will be evident, if upward pressure be applied to the middle of therod 11 this pressure will be transmitted to the middle points of the end-levers, while the levers will press the rollers upwardly against the platen or. the paper, and, owing to the central application of such pressure on the rod, the force applied to the levers will be equalized, thus equalizing the pressure as between the two ends of each paper-roller. At the same time, owing to the freedom for relative rotation and angular movements of the rollers and the levers, each roller is sufliciently free to accommodate itself to.any slight differences in the thickness of the paper or to compensate for an inacm curacies in the form of the platen or 0 either roller.

' As a convenient means for applying the resilient pressure to the middle of the rod 11,

a rock-shaft 12 is journalled, at its ends, in plates 13 which may be the usual end-plates of the carriage of the typewriter. An arm 14 is adjustably fixed to the middle of the rock-shaft, and the end of this arm is perforated to receive the rod 11, the connection at this point preferably being loose enou h to permit relative angular movements of the arm and the rod. At each end of the rockshaft 12 a coil spring 15, attached to an adjustable collar 16, acts to turn the rock-shaft in a direction to swing the arm upwardly and thus transmit the desired pressure and movement to the rod 11.

The cooperative action of the rollers and the platen 1s such as to tend to maintain them in position with their axes parallel, but to secure such parallelism more positively, without interfering with the compensating move- .ments of the rollers, means are preferabl provided in the form of links 17 of whic the rear ends have loose pivotal connection with the rod 11. The front ends of'these links are loosely pivoted upon the rock-shaft '12, between collars 18.-

Owing to the loose connections of the s 1 0 eral parts, as above described, it is desirable to provide means for preventing endwise movement of the rollers and their supporting mechanism. For this purpose a plate 19 is shown, fixed at its lower end to a part 20 of the carriage, this plate having a vertical slot which engages and guides one of the endlevers 9.

The invention claimed is:

Paper-roller mechanism, for a typewriter or the like, comprising two parallel rollers, two end-levers each having loose pivotal connections with the corresponding ends of said rollers, a rod loosely connected, at its ends,

' with intermediate points of the respective end-levers, a rock-shaft parallel with said rollers and rod, an arm fixed to the rockshaft and having a loose pivotal engagement with the middle of said rod, two links, each loosely pivoted, at its ends, to the rod and the rock-shaft, respectively, and a spring for r0- tating the rock-shaft in the direction to press the rollers against the pavprer.

CHESTER CRUMRINE. 

